Fix shell option with Node 7 (#48)

Node versions >= 6 are supporting the shell option.

Also added Node 7 to CI.

Author: johanneswuerbach

.travis.yml

@@ -4,3 +4,4 @@ node_js:
   - '0.12'
   - '4'
   - '6'
+  - '7'

appveyor.yml

@@ -15,6 +15,7 @@ environment:
     - nodejs_version: 0.12
     - nodejs_version: 4
     - nodejs_version: 6
+    - nodejs_version: 7
 
 # get the latest stable version of Node 0.STABLE.latest
 install:

lib/parse.js

@@ -8,7 +8,7 @@ var readShebang = require('./util/readShebang');
 
 var isWin = process.platform === 'win32';
 var skipShellRegExp = /\.(?:com|exe)$/i;
-var supportsShellOption = parseInt(process.version.substr(1).split('.')[0], 10) === 6;
+var supportsShellOption = parseInt(process.version.substr(1).split('.')[0], 10) >= 6;
 
 function parseNonShell(parsed) {
     var shebang;

test/test.js

@@ -486,7 +486,7 @@ extension\');', { mode: parseInt('0777', 8) });
                     });
                 });
             } else {
-                it.only('should use nodejs\' spawn when option.shell is specified', function (next) {
+                it('should use nodejs\' spawn when option.shell is specified', function (next) {
                     buffered(method, 'echo', ['hello &&', 'echo there'], { shell: true }, function (err, data, code) {
                         expect(err).to.not.be.ok();
                         expect(code).to.be(0);